Yes indeed, going via the Youtube dispute process may take a long time, which is why this not the preferred way to deal with claims. Have you tried clearing it via the Adrev form? This is the quickest way to clear claims from AdRev (other third-parties have similar forms).
I agree with you that the whole system is far from ideal, but as @Stockwaves said, this is a Youtube thing. Hopefully they will come up with a smoother process eventually.